diff --git a/Assets/Cryville.EEW.Unity/UI/StatusView.cs b/Assets/Cryville.EEW.Unity/UI/StatusView.cs
index cb61e91..204a1d1 100644
--- a/Assets/Cryville.EEW.Unity/UI/StatusView.cs
+++ b/Assets/Cryville.EEW.Unity/UI/StatusView.cs
@@ -12,8 +12,8 @@ namespace Cryville.EEW.Unity.UI {
 			_textView = GetComponent<TMP_Text>();
 		}
 
-		StringBuilder _sb = new();
-		char[] _buffer = new char[256];
+		readonly StringBuilder _sb = new();
+		readonly char[] _buffer = new char[256];
 		void Update() {
 			_sb.Clear();
 			_sb.AppendFormat(